Street Art is any art developed in public spaces — that is, "in the streets" — though the term usually refers to art of an illicit nature (as opposed to, for instance, government or community art initiatives). The term can include traditional graffiti artwork, though it is often used to distinguish modern public-space artwork from traditional graffiti and the overtones of gang territoriality and vandalism associated with it.
Whereas traditional graffiti artists have primarily used free-hand aerosol paints to produce their works, "street art" encompasses many other media and techniques such as wheatpasting, stickers, stencil graffiti, mosaic tiling, video projection and 3D sculpture. For these reasons street art is sometimes considered "post-graffiti". The term is also occasionally used to refer to guerrilla art. Street art can be found around the world and street artists often travel to other countries foreign to them so they can spread their designs. [From Wikipedia]